diff options
Diffstat (limited to 'poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml')
-rw-r--r-- | poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml index a125ad332..421364c2c 100644 --- a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml @@ -369,9 +369,8 @@ <para> These operators differ from the ":=", ".=", "=.", "+=", and "=+" - operators in that their effects are deferred - until after parsing completes rather than being immediately - applied. + operators in that their effects are applied at variable + expansion time rather than being immediately applied. Here are some examples: <literallayout class='monospaced'> B = "bval" @@ -420,18 +419,22 @@ FOO = "123 456 789 123456 123 456 123 456" FOO_remove = "123" FOO_remove = "456" - FOO2 = "abc def ghi abcdef abc def abc def" - FOO2_remove = "abc def" + FOO2 = " abc def ghi abcdef abc def abc def def" + FOO2_remove = " \ + def \ + abc \ + ghi \ + " </literallayout> The variable <filename>FOO</filename> becomes - " 789 123456 " + " 789 123456 " and <filename>FOO2</filename> becomes - " ghi abcdef ". + " jkl abcdef ". </para> <para> Like "_append" and "_prepend", "_remove" - is deferred until after parsing completes. + is applied at variable expansion time. </para> </section> @@ -796,17 +799,15 @@ <title>Key Expansion</title> <para> - Key expansion happens when the BitBake datastore is finalized - just before BitBake expands overrides. + Key expansion happens when the BitBake datastore is finalized. To better understand this, consider the following example: <literallayout class='monospaced'> A${B} = "X" B = "2" A2 = "Y" </literallayout> - In this case, after all the parsing is complete, and - before any overrides are handled, BitBake expands - <filename>${B}</filename> into "2". + In this case, after all the parsing is complete, + BitBake expands <filename>${B}</filename> into "2". This expansion causes <filename>A2</filename>, which was set to "Y" before the expansion, to become "X". </para> |